Timing device



F. LOEFFLER TIMING DEVICE Sept. 2, 1941.

Filed June 25, 1937 4 Sheets-Sheet l INVENTOR flmgg ATTORNEY Sept. 2, 1941. F. LOEFFLER 2,254,536

TIMING DEVICE Filed June 25, 1937 4 Sheets-Sheet 2 F/F/TZ ma /1m 7 INVENTOR BY flew-MA :5; ATTORNEY F. LOEFFLER TIMING DEVI CE Sept. 2, 1941.

Filed June 25, 1937 4 Sheets-Sheet 3 fF/TZ [Of/72f INVENTOR ATTORNEY Sept. 2, 1941. LQEFFLER 2,254,536

TIMING DEVICE Filed June 25, 1957 4 Sheets-Sheet 4 69/77 {off/10 INV'ENTOR BY fl mdak ATTORNEY Patented Sept. 2, 1941 UNITED STATES PATENT OFFICE 5 Claims.

This invention relates to timing devices, having particular reference to timing devices of the type wherein an electromagnetic oscillating motor operates intermittently to store up energy in a spring which drives a cooperating clockwork. The invention comprises improvements over the disclosures of United States Patents Nos. 1,993,411 and 2,000,600 and of copending application Serial No. 589,788 now Patent No. 2,089,280, granted August 10, 1937.

Generally, the object of this invention is to provide a novel device of the character indicated which shall be simple and eflicient in construction, and positive and economical in operation over a wide range of voltages.

More specifically, an object of this invention is to provide a novel device of the character indicated in which one spring shall serve for storing and transmitting energy from the motor to the clockwork, and for operating a switch that makes and breaks the motor circuit.

Another object of this invention is to provide a novel device of the character indicated, wherein the switch for controlling the motor circuit shall be arranged to make a positive and sudden pressure contact. to maintain a sliding pressure contact during the contact interval, and to produce a sudden and positive break of ,the contact at the end of the contact interval so that sparking and fouling are minimized.

Another object of this invention is to provide a novel device of the character indicated wherein energy shall be stored in a driving spring and shall be constantly transmitted directly to a driving gear of the clockwork.

Another object of this invention is to provide a device oi the character indicated, wherein the driving connection between the motor and the clockwork shall be so arranged that there is a minimum of lag and backlash when the motor tensions the driving spring.

A further object or this invention is to provide a device of the character indicated wherein the driving spring shall be so arranged that a constant torque is applied to the clockwork regardless of the degree of tensioning of the spring.

A further object of this invention is to provide a device of the character indicated wherein a means shall be provided for breaking the motor circuit if the device should cease to operate while the switch is in contact, so that damage to the device from overheating is obviated.

A further object of this invention is to provide a device of the character indicated wherein, it

desired, a sweeping or central second hand can be mounted in a novel manner.

A further object of this invention is to provide a device the character indicated which shall have a novel and simple hand-setting arrangement.

A still further object 01' this invention is to provide a novel device of the character indicated wherein a light shall be provided and the holding means (or the dial and glass shall also serve as a reflector.

A still further object of this invention is to provide a device of the character indicated which shall have a novel fastening arrangement for quickly and easily mounting it in a flat panel such as the dashboard of an automobile.

These and other objects of this invention, together withthe manner of achieving them, will become evident in the iollowing specification, taken together with the accompanying drawings, in which Fig. 1 is a rear plan view of a-device constructed in accordance with this invention with the casing broken away;

Fig. 2 is a sectional view taken along line 11-11 0! Fig. 1;

Fig. 3 is a iront plan view of the motor unit alone with the casing shown in section;

Fig. 4 is a section along the line IVIV of 30 Fig. 1. showing the positive or battery connection for the magnetizing coil and the heat-responsive fuse;

Fig. 5 is a section along the line V-V of Fig. 1, showing the negative or ground connection for 35 the magnetizing coil;

Fig. 6 is a section along the line VI-VI of Fig. 1, showing the connection between the coil and the switch;

Fig. 7 is a rear plan view of the clock unit of a modified embodiment of this invention having a sweeping or central second hand;

Fig. 8 is a section along line VIII-VIII of Fig. 7, showing the central second hand construc- 45 tion;

Figs. 9. 10 and 11 are plan views of the switch in three diilerent operating positions; Fig. 12 is a section along the line XIIXII of Fig. 9, showing the means for mounting the sev- 50 eral parts of the switch in relation to each other;

and

Figs. 13 and 14 are sections along the line XIII-XIII 01' Fig. 1, showing the punched lugs before and after being twisted to indicate a preferred construction for attaching the casing of the novel timing device to a fiat plate, as, for instance, the dashboard of an automobile.

In accordance with this invention a timing device may comprise a motor unit, indicated generally by A, and a cooperating clockwork, indicated generally by B. The motor unit may comprise a stator having a frame I of Bakelite or other suitable non-magnetic insulating material and a rotor 2 of magnetic material, rotatably mounted in the frame I and adapted to oscillate relatively to the stator and periodically to tension a spring 3 to store energy therein. The energy stored in the spring is constantly transmitted to the clockwork through flexible members or clicks 4 fixed to the rotor and engaging directly in a driving gear of the clockwork, as will hereinafter more fully appear. I

The frame I may be provided with an annular recess in which are fixed a plurality of U-shaped magnetic pole pieces 5 at equal circumferential distances and an annular magnetizing coil 1 having a positive or battery connection I and a negative or ground connection 5. An annular, non-magnetic, insulating washer Il may be provided for holding the coil I in place. Fixed in a centrally located opening through the frame I and substantially concentric with the coil 1 may be a bushing II having a rotor shaft I2 rotatably mounted therein. The rotor 2 is fixed to the front end of the shaft I2 by any suitable means and is preferably star-shaped, having a plurality of radial bars of magnetic material adapted to cooperate magnetically with the U-shaped pole pieces 5 of the stator, as shown in Fig. 3. The number of radial bars must be the same as the number of pole pieces. Fixed to the rear end of the rotor shaft I2 is a fiat member I3 of nonmagnetic conducting material, which serves as a lever to tension spring 3 when rotor 2 rotates in the direction shown by the arrows (Fig. 3) responsive to a current through coil I. The member I3 also serves as part of a switch indicated generally by C for making and breaking the circuit through coil I.

The switching mechanism may comprise a conducting member or brush I4 and a non-magnetic, non-conducting cam or lifting finger I5 pivotally mounted by means of a pivot I5 on member I3. The pivot I5 is preferably formed by bending down a portion of member I3, as shown in Fig. 12. The pivot I may be provided with a fiat, extending portion I6 for slidably supporting lifting finger I5. The brush I4 may be pivotally mounted relatively to frame I by any suitable means. Such means may comprise a U-shaped portion I'I adapted to hook into a groove in the head of a bolt II fixed to frame I by any suitable means, as shown in Fig. 6. The bolt I. may also serve to fasten and make contact with one end of coil I which extends through an opening I! in the back of frame I. The brush I4 is preferably provided with a hook into which one end of spring 2 is hooked, and a contact 2I of special material adapted to make contact with a contact cam 22 fixed to member I3. The lifting finger I5 is preferably provided with an opening 23 into which the other end of spring I is hooked. Stops 24 and 25 may be provided on frame I to limit the rotational motion of member I3 which also limits the motion of rotor 2. since both member I! and rotor 2 are fixed to rotor shaft I2 and thus rotate as a unit.

A stop 22' on member I2, preferably formed by bending down a portion of member I3, may be provided for cam I5. The stop 22" may have a fiat, extending portion 22 for slidably supporting cam I5.

Brush I4 may be provided with a slot I4 through which lifting finger I5 extends, and an outwardly extending fiat portion 28 adapted to cooperate with lifting finger I5, as will hereinafter more fully appear. Slot I4 serves to guide and slidably support both brush I4 and lifting finger I5 so that they maintain their proper relative position at all times.

Spring 3 is tensioned between brush I4 and lifting finger I5 and thus constantly tends to press brush I4 into contact with contact cam 22 and lifting finger I5 against stop 22. Spring 5 also pulls member I3 through pivot I6 against stop 24 in normal non-operating position. Thus an electric circuit is made from battery connection 5 through coil 1, bolt I8, brush I4, contact 2I, contact cam 22, member II, shaft I2, bushing II, and through a suitable conductor 26 from bushing II to the ground connection 5.

When current passes through this circuit the coil 1 magnetizes pole pieces 6, which attract the magnetic bars of the rotor 2 and cause it to rotate in the direction indicated to a position such as is indicated by the dotted lines in Fig. 3. The switch at the same time passes through the cycle of operations indicated in Figs. 9, 10 and 11. Lifting finger I5 rotates with member I3 until hook portion 21 of lifting finger I5 engages fiat portion 28 of brush I4, after which lifting finger I5 pivots around pivot I6 away from stop 22 until the position shown in Fig. 10 is reached. It will be seen that up to this point a sliding pressure contact has existed between contact 2I and contact cam 22 which keeps the contacts clean and effective. The portion 28 of brush I4 now suddenly clears the hook portion 21 of lifting finger I5 and is snapped out of contact by a curved portion 28 thereof under tension of spring 3, which pulls lifting finger I5 back against stop 22 as shown in Fig. 11. This breaking of contact preferably occurs when the bars of rotor 2 have covered one-quarter to one-third of pole pieces 5, momentum carrying the rotor an additional distance, further tensioning spring 3. The energy stored in spring I is now transmitted through lifting finger I5, pivot I6, member I3, rotor shaft I2, rotor 2, and clicks 4, to a driving wheel 39 of the clockwork over which clicks 4 have slid when rotor 2 was tensioning spring 3. Since the speed of this action is so great, there is no back drag and no appreciable interruption in the force applied to the driving gear. As the clockwork is driven by spring 3, rotor 2 gradually returns to its initial position until brush I4 suddenly drops oi! of curved surface 2! into contact with contact cam 22, when the cycle is repeated.

It will be seen from the foregoing description that as rotor 2 tensions spring 3, the lever arm through which spring! acts to drive the clockwork, becomes less. This results in substantially constant torque being applied to the clockwork regardless of the degree of tensioning of spring I. It will also be seen that spring 3 serves as a single means for storing energy to drive the clockwork and for operating the switch to make a sudden contact. to hold a pressure contact during the contact period, and to break the contact suddenly responsive to rotation of the rotor.

The clockwork denoted generally by B may comprise two parallel fixed plates 30 and II, spaced and held together by spacing lugs 32, a dial backing plate 32, a dial 34, a central or minute shaft 35 rotatably mounted in plates 33 and II and carrying a minute hand 35 fixed to the end thereof, an hour shaft 31 rotatably mounted on the shaft 35 in geared relation thereto in a well-known manner and carrying an hour hand 33 fixed to the end thereof, a center or driving gear 33 frictionally engaging the central shaft 35 through a washer 43 fixed to shaft 35 and a spring washer 4|, and a gear train driven by the center gear 33 and controlled by an escapement, a balance wheel 42, and a hairspring 43, all of well-known, conventional arrangement and therefore not fully shown in the drawings. A shaft 44, together with cooperating mechanism, may be provided for adjusting the hair spring 43 and regulating the clock movement. For attaching the clockwork to the frame I of the motor unit there may be provided a ring plate 45 fixed to plate 33 by screws 45, spacing lugs 41 fixed to ring plate 45, and bolts 43 passing through openings in frame I and screwing into lugs 41, as shown in Fig. 5. The motor unit and clockwork are preferably mounted relatively to each other in such a manner that rotor shaft l2 and central shaft 35 are in substantially axial alignment.

It is an important part of this invention that the flexible clicks 4 fixed to one of the bars of rotor 2 engage directly in the teeth of center gear 33 so that energy stored in spring 3 by rotor 2 is transmitted directly to center gear 33 without any intermediate gears or linkages. Openings (not shown in the drawings) are provided in plates 33 and 3| to accommodate clicks 4 over the full range of movement of rotor 2. A plurality of clicks is preferably provided having spaces between their ends slightly greater than the pitch of the teeth of center gear 33, so that each click drops in at a different instant when rotor 2 tensions spring 3 and drag and backlash are minimized. For smoothest operation, the space between the click ends should be where n is the number of clicks and p is the pitch of the teeth in which they engage. with such a ratchet mechanism, the action is the same as a single click engaging n times the number of teeth in the same linear distance.

In a preferred embodiment of this invention, a novel means is provided for setting the hands relatively to the clockwork from the back of the motor unit. In this embodiment, the rotor shaft I2 is hollow and has loosely mounted therein a shaft 43 having a knurled knob 53 fixed to the outer end thereof and a crank 5| at the other end thereof. Fixed to the inner end of the central or minute shaft 35 may be a flat disk 52 having a slot 53 therein adapted to cooperate with crank 5|, which fits rotatably and slidably into the slot 53. Then by turning knob 53 shaft 35 can be turned relatively to center gear 33 against the friction of washer 4|, even though wide misalignment between shaft 35 and rotor shaft l2 exists. With shaft 35, hands 35 and 33 are turned in geared relation to each other.

For preventing damage to the coil or any other part of this device, if the rotor should fail to operate when the switch is closed or in contact, there is provided in accordance with this invention means responsive to heat generated in the coil for breaking the circuit therethrough before any damage can be done. Such means may comprise a low-melting alloy conductor 54 interposed 7 in the circuit between the positive terminal 3 and the coil 1. The conductor 54 may be held at one end by a bolt 55, to the upper end of which the terminal 3 is connected, and a nut (Fig. 4), and at the other end by a bolt 51 which also holds one end of the coil 1 extending through an opening 53 in frame I. The conductor 54 melts responsive to heat generated in coil I, but not within itself, thus breaking the circuit through coil 1.

A modified form of clockwork in accordance with this invention, having a novel central or sweeping second hand arrangement, is shown in Figs. 7 and 8. In this embodiment three parallel, spaced plates 53, 53v and 5| are provided. A shaft 52 is rotatably mounted in plate 53 and carries a second hand 53 fixed to an end thereof. A hollow minute shaft 54, surrounding and substantially concentric with shaft 52 but spaced therefrom, is rotatably mounted in plates 53 and 5| and carries a bushing 55 frictionally engaging it on which is mounted a minute hand 55. A bearing 51 between shaft 52 and shaft 54 provides the only other positive mounting for shaft 52 besides plate 53. Rotatably mounted on bushing 55 and geared in relation thereto in a wellknown manner. is a shaft 53 carrying an hour hand 53. A center or driving gear I3 is fixed to shaft 54 and is driven by clicks 4 fixed to rotor 2 in the same manner as previously described. Power is transmitted from gear l3topinion '||,from gear 12 mounted on pinion H to pinion 13 mounted on shaft 52, and from gear" fixed to pinion 13 to pinion 15 which is fixed to escape wheel 15. This novel construction is of advantage because it allows relatively wide misalignment between shafts 52 and 54 without causing binding therebetween or interfering with proper operation in any way. A shaft 15 cooperating with a conventional gear train may be provided for setting hands 55 and 59 independently of shaft 54 against the friction between bushing 55 and shaft 54.

A timing device in accordance with this invention may be enclosed in a suitable casing I1 which may be secured to the frame I by any suitable means such as the screws 13 and the rubber grommets 13 fixed to bolts which also serve to hold the motor and clockwork together and the positive and negative terminals 3 and 3, respectively, of the electric circuit. These latter terminals may be additionally protected by a small casing 33 fixed to casing 11 in any suitable manner. For protecting the set knob 53 which pro trudes through an opening in casing 11 against contact and dust, a removable cap 5| is provided therefor, which may be removably secured to casing 13 in any suitable manner.

Mounted within casing 11 in such a manner that it can be easily removed, may be an electric light 32 for lighting up the hands and dial of the clockwork. A glass 33 which may also carry numbers to indicate divisions of time, may be provided in front of dial 34 and held in place by suitable means such as member 34 and bezel 35 crimped over the edge of casing 11. The member 34 is preferably polished to act as a reflector for directing light from lamp 32 over dial 34 and into the edge of glass 33 for illuminating the same.

Referring now to Figs. 12 and 13, there is shown a novel means for attaching the novel timing device to a flat plate, as, for example, the dashboard of an automobile. A plurality of lugs 35 punched out with the casing 11 are provided to be slipped through slots 31 in the cooperating plate, after which the lugs can be twisted to secure the casing to the plate. This provides a quick, firm and inexpensive means of mounting the casing l'l wherever desired.

It is, of course, contemplated that certain changes, substitutions and modifications may be made in the novel timing device hereinbefore described without departing from the spirit or scope of this invention, as defined in the appended claims. It is, for instance, possible to insert a spiral, energy-storing spring between clicks 4 and center gear 30, in which case rotor 2 will go through several cycles in quick succession until the tension of this second spring balances the tension of spring 3, after which cycles will repeat in their normal period. This would permit the current source to be out off for a considerable length of time without interfering with the operation of the clockwork which would be driven by the energy stored in the second spring.

What is claimed is:

1. In a timing device, a motor having a stator and a rotor, a hollow shaft for rotatably mounting said rotor, a clockwork cooperating with said motor, a central shaft forming part of said clockwork in substantially axial alignment with said rotor shaft and carrying a time-indicating means at one end thereof, and means including a member fixed to the other end of said central shaft and a crank rotatably mounted in said rotor shaft and rotatably and slidably cooperating with said member for setting said time indicating means.

2. In a timing device, a motor having a stator and a rotor, a hollow shaft for rotatably mounting said rotor, a clockwork cooperating with said motor, a rotatably mounted central shaft for said clockwork in substantially axial alignment with said rotor shaft and carrying a minute hand at one end thereof, an hour shaft rotatably mounted on said central shaft in geared relation thereto and carrying an hour hand at the end thereof, and means including a disk having a slot therein fixed to the other end of said central shaft and a shaft rotatably mounted in said rotor shaft and having a crank at one end thereof adapted to cooperate with said slot for setting said hands independently of said clockwork.

3. In a timing device, a motor having a stator and a rotor, a clockwork cooperating with said motor, a casing for said motor and clockwork having an opening in the rear thereof, a hollow shaft for rotatably mounting said rotor, a rotatably mounted central shaft for said clockwork in substantially axial alignment with said rotor shaft and carrying a minute hand at one end thereof, an hour shaft rotatably mounted on said central shaft in geared relation thereto and carrying an hour hand at one end thereof, means including a disk having a slot therein fixed to the other end of said central shaft and a set shaft rotatably mounted in said rotor shaft and having a crank at one end thereof adapted to cooperate with said slot for setting said hands inde-- pendently of said clockwork, means for turning said set shaft protruding through the opening in said casing, and cover means removably secured to said casing and covering said opening for protecting said turning means.

4. In a timing device, a motor comprising a stator having a coil and a rotor arranged to rotate when an electric current is passed through said coil; a clock work cooperating with said motor; an electric switch adapted to close an electric circuit through said coil and cause rotation of said rotor; and a single spring for storing all the energy produced by intermittent rotation of said rotor, which spring constitutes the sole power means for closing said switch, for holding said switch closed while said rotor rotates through a predetermined angular distance, for opening said switch after said rotor has rotated through said predetermined angular distance, for driving that clockwork and for returning said rotor to starting position.

5. In a timing device in cooperation with a clockwork, a switch comprising contacts and a contact making and a contact breaking member, a single spring, a motor comprising a coil, a stator and a rotor for intermittently furnishing the energy to be stored in said single spring, said spring being fioatingly suspended between said contact making and breaking members so that it causes the sudden closing of the contacts, the holding of the contacts in closed position during the rotation of the rotor through a predetermined angular distance, and the sudden opening of the contacts after said rotor has moved through said angular distance and the return of the rotor into starting position while driving the clockwork.

FRITZ LOEIF'FLER. 

